<!DOCTYPE html>
<html lang="en">
<head>
  <title>Document</title>
</head>
<body>
  
  <div id="app">
    <a href="#/home">home</a>
    <a href="#/about">about</a>

    <div id="content">Default</div>
  </div>

  <script>
    const contentEl = document.querySelector('#content');
    window.addEventListener("hashchange", () => {
      switch(location.hash) {
        case "#/home":
          contentEl.innerHTML = "Home";
          break;
        case "#/about":
          contentEl.innerHTML = "About";
          break;
        default:
          contentEl.innerHTML = "Default";
      }
    })
  </script>

</body>
</html>